DISEASE CHARACTERISTICS: Histologically confirmed stage Tis, Ta, or T1 bladder carcinoma No stage B1 disease or greater No locally invasive or metastatic disease by CT or MRI No upper urinary tract disease Measurable persistent or recurrent superficial disease after standard treatment with intravesical BCG Stage Tis disease must fail second course of BCG if complete response achieved with first course of BCG Prior maximal transurethral resection High-grade T1 or Tis disease must be ineligible for cystectomy